Study: majority of middle-aged Americans at risk of developing hypertension

FDA Consumer, May-June, 2002

Middle-aged Americans face a 90 percent chance of developing high blood pressure at some time during the rest of their lives, according to a new study supported by the National Heart, Lung, and Blood Institute (NHLBI).

However, the study also had some good news for Americans: The risk of developing severe degrees of high blood pressure has decreased in the past 25 years, due in part to improved treatment.

"Ninety percent is a staggering statistic and cause for concern," says Health and Human Services Secretary Tommy G. Thompson. "This finding should energize Americans to take steps to protect themselves against high blood pressure."

"Americans have to better understand their risk of developing high blood pressure," agreed NHLBI Director Claude Lenfant, M.D. "They cannot adopt a wait-and-see approach. If they do, chances are they will find themselves with high blood pressure and that puts them at increased risk for heart disease and stroke."

According to Lenfant, high blood pressure is easily diagnosed and can be prevented by adopting certain lifestyle measures--don't smoke, follow a healthy eating plan that includes foods lower in salt and other sources of sodium, maintain a healthy weight, be physically active, and if you drink alcoholic beverages, do so in moderation. For those who already have high blood pressure, it's important that they properly control it with these lifestyle measures and medication.

The study, based on data from the NHLBI's landmark Framingham Heart Study (FHS), appears in the Feb. 27, 2002, issue of the Journal of the American Medical Association. The National Institute of Neurological Disorders and Stroke also contributed support to the research.

High blood pressure, or hypertension, is a measure of the force of blood within blood vessels. It is recorded as two numbers--the systolic (the force of the blood as the heart beats) over the diastolic (the force of the blood as the heart relaxes between beats). The diagnosis of hypertension occurs if either or both are high--140/90 mm Hg or above.

"Lifetime risk" estimates the chance that someone at a given age will develop a particular disease during his or her remaining years of life. The FHS began in 1948 with 5,209 participants without cardiovascular disease who were ages 28 to 62. Participants underwent medical examinations every 2 years. The hypertension study includes 1,298 of the original participants--those who had not developed hypertension by 1975. Researchers calculated lifetime risk for two ages, 55 and 65.

Additionally, the researchers compared lifetime risk from two time periods, 1952-1975 and 1976-1998. They examined the results to see if any trends emerged in participants' risk for developing hypertension. Calculations were based on the current U.S. life expectancies for 55-and 65-year-olds, which are 80 and 85 years, respectively.

The investigators found that the lifetime risk of developing hypertension was about 90 percent for men and women at both ages. Further, more than half of the participants age 55 and about two-thirds of those age 65 went on to develop hypertension within 10 years. Both men and women had a nearly 60 percent chance of being prescribed blood pressure-lowering drugs.

Ramachandran Vasan, M.D., associate professor of medicine at Boston University School of Medicine and a coauthor of the study, cautions that the study was not ethnically diverse. He stresses that the lifetime risk of developing hypertension varies among individuals and depends on the presence of risk factors.

NHLBI information on cardiovascular disease and an interactive Web page, "Your Guide to Lowering High Blood Pressure," can be found online at www.nhlbi.nih.gov/hbp/.>

COPYRIGHT 2002 U.S. Government Printing Office

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